Luminous scale rotameter



. June 17, 1941. w. H. GERBER LUMINOUS SCALE ROTAMETER Filed March 18,1940 Watented June 17, 1941 2,246,464 Lemons scan: no'rsms'ran Walter B.Gerber, l'hlladelplna, Pa., asslgnor to Schutte Q Koerting Company,Philadelphia, Pa a corporation of Pennsylvania Application March 18,1940. Serial No. 324,553

3 Claims. (Cl. 13-409) The principal object of the present invention isto provide a rotameter which can be used satisfactorily in dark placessuch as occur inoonnectlon with photography, and which, when so used,does not give out objectionable light although it can be easily andaccurately read in the dark.

Another object of the invention is to provide simple, reliable andemcient means for illuminating a gauge or measuring device 01' therotameter without illuminating the space surrounding the instrument.

Other objects 01' the invention will appear from the followingdescription at the end oi which the invention will be claimed. a

Generally stated, the invention comprises, means for edge-lighting atleast one of the elements,- which is transparent, oi the measuringdevice or gauge of a rotameter. The present application is directed tothe of the invention in. dark places which are required to be kept darkby reason of requirements of the work or some of it that is done inthem.

The invention also comprises the improvements to be presently describedand finally claimed.

In lthe following description reference will be made to the accompanyingdrawing to 1 larged scale and illustrating parts shown in Figure 3.

Referring to Figures 1 and 2 and generally stated, the rotameter as awhole is of standard construction. I and 2 indicate the heads which arespaced apart by columns 3. Liquid to be rnessiu'ed enters and leaves atth heads and flows through the transparent tube 4. The position of thefloat 5 indicates the rate of how. In connection with a standardrotameter such as has been briefly described, the description of theinvention will be given. I is a pole rod and it passes through asuitable aperture in the float i. One feature of the present inventionis that the pole rod 6 is made oi "Lucite" glass or any transparentmaterial adapted for edge-lighting. On

the pole rod 6 is a scale consisting of a number 01' indentations orscratches l. The pole rod 3 is shown as mounted at the base of theinstrument in a tube 8 which serves as a stop and sit the top the polerod Ii extends through the head i and up into a closed chamber 9. In thechamber 8 is a lamp or light it arranged opposite the end of the rod 6and in a positlonto edge-light it.

By the described construction, and in accord- 81166 with the law Ofedge-lighting, the pole rod itself is very little, or not at all,illuminated but the indentations or scratches oi the scale I areilluminated in such a way that they are readily seen. H indicates alight filter arranged at the end of the pole rod 6 and between it andthe source of light ill. The scale or markings I should he at the backof the rod in respect to the eye of the observer, because in that waythey are more pronounced. Ii the sides of the notches I are at lightfrom the lamp In is directed horizontally which is something oi anadvantage but not in all cases necessary.

when in use, the observer notes a black line at the top and bottomor'the float and he refers to the black line at the top of the float inits relation to the scale which is marked on the pole. Thus therotameter includes a gaugeor measuring device having the float as anindex element and the marking on the pole rod as a scale element and, ashas been said, the waleelement is of transparent material and isedge-lighted so that its markings are illuminated while little or noother light; is visible.

The construction and mode of operation of the modification shown inFigs. 3 and 4 are substantially as described except that the tube 4 isof transparent material and has upon it the scale markings I This tubeis edge-lighted by the source of light Ill through a plane or lightfilter glass partition: ll which also servesthe purpose of excludingfluid or liquid, being memured, from the light source.

It will be obvious to those skilled in the art to which the inventionrelates that modifications may be made in details of construction andarrangement and in matters of mere form without departing from thespirit of the invention which is not limited in respect to such matters.

I claim:

1 Means for fitting rotameters having a float or rotor and a transparentmetering tube for use in the dark comprising, a cylindrical pole rod 01!transparent material arranged in the metering tube and in respecttowhich the rotor is movable, a notched scale on the cylindrical surfaceof the rod, and a source of light arranged to edgelight the pole rod andilluminate the scale.

light arranged at the top of the rotameter and into which the end of thepole rod projects, and a lamp in said chamber opposed to the end of thepole rod.

3. In a rotameter having spaced heads provided with fluid ways by whichthe fluid to be measured enters and leaves the rotameter and having arotor elemenit, the combination of a chamber closed against the emissionof light and mounted outside of the fluid way of one of the heads, alamp in the chamber, a transparent partition separating a fluid way fromthe interior oi the chamber and from the lamp, and a cylindrical scaleelement of transparent material extending between the heads and into thefluid way of one of them with its end confronting the lamp and havingnotches onits cylindrical surface which are to be edge lighted by thelamp.

WALTER H. GERBER.

